Lock.



S; D. POLSEN.

LOCK.' APPLIGATION FILED-AUG. 19, 1910..

991,363. Y Patented May 2,1911..

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SAMUEL D. POLSEN, 0F BRIDGEPORT, CONNECTICUT.

LOCK.

Specification of Letters Patent.

Application filed AugustAlS, 1910.

Patented May 2, 1911.

serial No. 578,036.

To all whom 'it 'may concern:

Be it known that I, SAMUEL D. FoLsnN, a citizen of the United States,and resident of Bridgeport, in the county of Fairfield and State ofConnecticut, have invented certain new and useful Improvements in Locks,of which the following is a specification.

This invention relates to new and useful improvements in spring lockssuch as are commonly used upon sliding doors, as for instance, cardoors, barn doors, and the like.

It is the purpose of my invention to provide an improved form of lockwhich will require a hollow internally and externally threaded key tooperate the same; to construct the lock so that it will be difficult topick the same and wherein the operating arm and lever will have to bereturned to their normal position before the key can be removed, andfurther to generally improve the construction of locks of this class ina way that the same may be manufactured at a comparatively low cost. Inthis class of locks the same style of key is intended to serve for anumber of locks so that when applied to car doors a single key in thehands of a local freight agent will suflice for all cars fitted with myimproved form of lock.

With these and other objects in view the invention consists in theconstruction and novel combination and arrangement of parts, hereinafterfully described, illustrated in the accompanying drawings, and pointedout in the claims hereto appended, it being understood that variouschanges in the form, proportion, size, and minor details of constructionwithin the scope of the claims may be resorted to without departing from-the spirit or sacrificing any of the advantages of the invention.

Similar characters of reference denote like or corresponding partsthroughout the several figures of the accompanying drawings forming apart of this specification, and upon which- Figure 1 shows a front sideview of my improved form of lock in its normal position. Fig. 2 is asimilar front elevation of lock with front plate removed. Fig. 3 is aslightly enlarged vertical cross section of the lock, taken on line 3-3of Fig. 2, and Fig. 1 is a detached perspective view of the key foroperating the lock.

Referring in detail to the characters of reference marked upon thedrawings 10 represents the back member of the lock case and 11 the frontof the case, which parts are secured together in any suitable manner.The back of the case 10 is recessed to accommodate the operativemechanism of the lock and the flange 12 of the front of the case. Acylindrical extension 13 is formed on the back of the case to produce abearing for the key socketed rocker arm 14: mounted therein. Theextended portion 15 of t-he arm is designed to throw back and forthbetween the lugs 16 formed upon the case, and against the resistance ofthe spring actuated latch 17. This latch is pivoted to a pin 1S securedin the case, and is provided with a spring 19 for holding the free endof the lever against the operating arm. The fixed end of this spring issecured to a second pin 20 held in the case and the free end of thespring is held against the latch by a lug 21 also secured upon theinside of the case. The forwardend of the latch is notched shown toengage any suitable forin of holding bolt, not shown. The front of thecase is provided with an extension 22 which has an opening through intothe case, that is provided with an internal left hand thread 23 throughwhich the key 24: is turned for insertion into the lock.

The hollow operative end portion 25 of the key is threaded both insideand outside and after passing through the key hole enters the annularspiral socket 26 within the hub of the rocker arm. The post 27 that iscentrally and longitudinally disposed within the key hole is secured tothe back of the lock case in any suitable manner, as for instance, bythreading, as shown. The inner case 28 of the hub of the rocker arm isloose upon the inner reduced end 29 of the centering post 27. Inpractice the inner cylindrical end of the key loosely fits over thepost, which latter is intended to form an pbsltruction against anyattempt to pick the oc t.

The action of the spring 19 serves the double purpose of holding theinner end of the latch up against the rocker arm 14 which is also heldin its normal position as shown in Fig. 2. This position of the arm issuch as to insure the proper registration of the threads of the arm withthose of the key hole so as to allow the threaded end of the key to befreely turned through the key hole and into the threaded socket of thearm until the key fetches up against the bottom as shown in Fig. 3,whereupon a further turn of the key causes the arm to also turn and liftthe latch. The key cannot be removed until it and the arm are firstturned backward, until the arm strikes the upper lug 16 as shown in Fig.2. A further turn of the key causes it to back out of the socket andhole, and thereby leaving the parts again in readiness for a futureinsertion of the key as in a further operation of the lock.

The foregoing construction embodying a threaded key hole in connectionwith a rocker arm having an annular threaded socket to receive aninternally and externally threaded hollow key serves to produce aneffective lock that is diflicult to operate except by the aid of aproper key.

Having thus described my invention what I claim and desire t0 secure byLetters Patent is,

1. In a lock of the class described the combination of a casing having athreaded key hole, a rotary rocker Varm mounted within the casing andhaving an annular internally and externally threaded key socket, meansto normally hold the said arm in position so that its threaded socketnormally registers with the threads of the key hole, and a latch to beoperated by the said rocker arm.

2. In a lock of the class described the combination of a casing having athreaded key hole, of a rocker arm mounted within the casing and heldagainst lengthwise 1nove ment and provided with a threaded key socketadapted to receive a hollow and externally threaded key whereby said armis turned within its bearings, and a latch bolt in contact with the armand adapted t0 be operated thereby.

8. In a lock of the class described the combinaton of a casing having athreaded key hole, and a key post secured to the casing, a rocker armmounted to turn upon the post but held against lengthwise movement andprovided with an externally threaded central core to receive theinternally threaded key barrel, and a latch bolt to be operated by thesaid arm.

Signed at Bridgeport in the county of Fairfield and State of Connecticutthis 18th day of August A. D., 1910.

SAMUEL D. POLSEN.

Witnesses:

C. M. NEUMAN, GEO. R. BURNER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

